The existing specifications and studies mainly focus on the scenarios that the spherical charges are ignited at the central point and explosion is in free air, while the studies of the blast loadings of cylindrical charges air explosion, especially the reflected overpressure acting on the structure, are relatively limited. The blast loading calculation formula for spherical charge cannot be applied for cylindrical charge as attributed to the parametric influences such as scaled distance, length-to-diameter ratio, ignition method, azimuth angle, incident angle and relative location of reflected plane. To explore the incident and reflected blast loadings of cylindrical charges air explosion, firstly, three shots of explosion test of the single-end ignited cylindrical TNT charge were conducted. The corresponding numerical simulations are conducted based on the finite element program AUTODYN, and the applicability of the adopted finite element analysis method is verified by comparing with the experimental incident and reflected overpressure-time histories of spherical and cylindrical charges air explosion of tests, as well as the peak incident overpressure-scaled distance relationship of unified facilities criteria (UFC) 3-340-02 of spherical charges air explosion. Furthermore, the numerical simulations of more than 1000 sets of cylindrical charges air explosion scenarios considering the scaled distance, length-to-diameter ratio, ignition method, azimuth angle and rigid reflection are carried out based on validated finite element analysis method. The distribution characteristics of peak overpressure, maximal impulse of the incident blast wave and the corresponding shape factors are examined and discussed. The judging criteria and determination methods for the critical scaled distance of peak overpressure and maximal impulse are proposed by using data fitting, and the variation law of the reflected peak overpressure and the rigid reflection coefficient are revealed. Finally, a calculation method for the incident and reflected blast loadings of cylindrical charges air explosion is proposed and experimentally verified by 360 sets data. The method can rapidly predict the blast loadings on building structures, and provide reference for evaluating the ammunition damage efficiency, analyzing structural dynamic response and failure, as well as for the corresponding blast-resistant design. © 2024 Explosion and Shock Waves. All rights reserved.
